Asteromassaria  

Anamorph: where known, conidiomata acervular, belonging to the form-genus Scoliciosporium.

Teleomorph: ascostromata perithecial, large, oblate to oblate-spherical or oblate-conical, scattered or in small clusters, initially immersed within the host tissues but becoming erumpent to varying degrees, sometimes surrounded by triangular radiating bark fissures. Ostiolar region central, hardly to distinctly papillate. Ascostromatal wall thick laterally, thinner above and around the ostiolar region, composed of outer layers of elongate to angular dark brown cells and an inner layer of flattened hyaline cells. Interascal tissue of narrow pseudoparaphyses, septate, branched and anastomosed, developing within a gelatinous matrix.  Asci very large, clavate, very thick-walled, fissitunicate, with a short tapering base and a rounded apex with a conspicuous ocular chamber, not staining blue in iodine, 8-spored. Ascospores usually arranged biseriately, very large, fusiform to fusiform-ellipsoidal, the ends obtuse to rounded, with a strongly constricted median to slightly submedian primary septum and sometimes two secondary septa that may or may not be constricted, very thick-walled, at first hyaline and smooth-walled, hyaline or mid brown at maturity, when hyaline at maturity often becoming brown and minutely ornamented when senescent, surrounded by a very conspicuous gelatinous sheath within the ascus that expands greatly after discharge.